Deep Silver has acknowledged that it accidentally released an "incorrect version" of apocalyptic zombie shooter Dead Island on the North American Steam service, pledging to patch the title as quickly as possible.

Early players and reviewers have reported widespread technical problems with the title, including game freezes and crashes, graphical issues, and odd in-game behavior such as the ability to walk through walls.

"We deeply regret that an incorrect version of Dead Island was inadvertently made available to players on Steam launch in North America," Deep Silver spokesperson Aubrey Norris told Gamasutra.

The company also promised that a patched version of the game would be made available "ASAP," and that the issue would not affect Friday's international launch of the game. Deep Silver has already announced a release day patch intended to fix 37 separate issues with today's release.

Players that have dug into the code for the release have uncovered evidence suggesting that the version currently on Steam is a development build that contained elements of the Xbox 360 version. Deep Silver has yet to comment on this possibility.